Strand advancing apparatus



July 24, 1956 D. E. KOERNER STRAND ADVANCING APPARATUS 3 SheetsSheet 1 Filed July 25 1951 lNl ENTOR D. E KOERNER BY ATTORNEY y 1955 D. E. KOERNER STRAND ADVANCING APPARATUS C5 Sheets-Sheet 2 Filed July 25, 1951 by m6 lNl/EN TOR D. E. KOERNER BY ATTORNEY July 24, 1956 D. E. KOERNER 2,755,917

STRAND ADVANCING APPARATUS Filed July 25, 1951 s Sheets-Shet s lulull l lllfllllf ATTORNEY United States Patent STRAND ADVANCING APPARATUS Dan E. Koerner, East Troy, Wis., assignor, by mesne assignments, to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Application July 25, 1951, Serial No. 238,521

2 Claims. (Cl. 203-300) This invention relates to strand advancing apparatus, and more particularly to magnetic apparatus for advancing a plurality of metal strands at a constant linear speed and under constant tension.

In the electrolytic production of copper-clad steel strands, it is desirable to advance a plurality of steel strands simultaneously and continuously from individual supply reels through an electroplating apparatus in predetermined spaced relationship at a constant linear speed and under constant tension. Usually the strand advancing means is positioned at the exit end of the electroplating apparatus, and the strand supply reels are maintained in stationary positions at the beginning of the electroplating apparatus so that the trailing ends of the strands being advanced through the apparatus may be connected to the leading ends of strands provided on auxiliary supply reels, thereby providing substantially continuous advancement of the strands through the apparatus. Since the supply reels are stationary, strand tensioning means must be positioned adjacent to the supply reels to hold the linear speed of the strands to such a value that the advancing means maintains a predetermined tension in each strand. Usually a strand is advanced from a stationary reel by a capstan and the strand makes one or more complete wraps around the capstan to insure a tight grip on the strand. However, such a capstan is not suitable where a plurality of strands are involved, and no satisfactory device has been developed heretofore to advance a plurality of strands individually at a constant linear speed and under constant tension.

An object of the invention is to provide new and improved strand advancing apparatus.

Another object of the invention is to provide new and improved magnetic apparatus for advancing a plurality of metal strands individually at a constant speed and under constant tension.

A strand advancing apparatus embodying certain features of the invention may include a plurality of aligned, spaced annular members made of magnetic material and rotatable about a central axis. The annular members have their adjacent edges beveled to form peripheral grooves therebetween designed to receive strands to be advanced by the members. Means positioned within the annular members are provided for producing an annular magnetic field around the grooves which holds the strands firmly in the grooves, so that when the members are rotated at a constant rate they advance the strands at a constant linear speed.

"Other objects and advantages of the invention will appear from the following detailed description of a specific embodiment thereof, when read in conjunction with the appended drawings, in which:

Fig. 1 is a schematic side elevation of an apparatus for advancing a plurality of strands through an electroplating apparatus in accordance with certain features of theinventi'on;

Fig. '2 is a plan View of a portion of the apparatus shown in Fig. 1;

2,755,917 Patented July 24, 1956 Fig. 3 is an enlarged vertical section taken along line 3-3 of Fig. 1;

Fig. 4 is a further enlarged fragmentary section of a portion of the apparatus shown in Fig. 3;

Fig. 5 is an enlarged vertical section taken along line 5-5 of Fig. 3.

Referring now to the drawings and more particularly to Fig. 1, there is shown a schematic arrangement of an apparatus designed to advance a plurality of steel strands 10-10 from left to right through an electroplating apparatus indicated generally at 12, which is designed to deposit copper electrolytically on the strands to form copper-clad strands 13-13. Only three of the steel strands are shown for purposes of illustrating the invention, but it is to be understood that the number of strands may be varied as desired and may run as high as 25 strands. The electroplating apparatus 12 does not form a pertinent part of the present invention and hence will be described herein only insofar as is necessary for a complete understanding of the invention.

The electroplating apparatus 12 includes an elongated trough 15, in which are positioned a series of shallow, rectangular tanks 16-16, only three of which are shown to illustrate the general construction of electroplating apparatus. The several tanks 16-16 are filled with cleaning solutions and electroplating solutions, and are arranged in the trough 15 to electrolytically clean and pickle the steel strands 10-10 and thereafter to deposit copper electrolytically on the steel strands as they are advanced through the electroplating apparatus. The strands pass under upper contact rollers 17-17 and over lower contact rollers 18-18 journaled rotatably in the side walls of the trough 15. Each of the rollers 17-17 and 18-18 is provided with equally spaced peripheral grooves 19-19 which maintain a predetermined spaced relationship between the strands as they are advanced through the tanks 16-16. The tanks 16-16 are connected to a positive D. C. potential, and the rollers 17-17 and 13-18 are connected to a negative D. C. potential, so that the solutions contained in the tanks 16-15 clean the steel strands electrolytically and deposit copper electrolytically on the strands to form the copperclad strands 13-13. The contact rollers 17-17 and 18-18 are driven by an endless belt 20 connected to be driven by an electric motor 21, so that the rollers tend to advance the strands from left to right as viewed in Fig. 1.

The steel strands 10-10 (Fig. l) are withdrawn from supply reels 23-23 positioned in a stationary manner on stands 24-24 mounted on a support 25 by a mag netic capstan indicated generally at 28. The capstan 28 is mounted on a support 29 adjacent to the left end of the apparatus 12, and is driven by an electric motor 30 at a constant rate of speed. Each individual strand 1%) passes around an idler sheave 33 and a brake sheave 34 mounted on an elongated support 35. The brake sheaves 34-34 guide their respective strands to a bank of sheaves 37-37 which fan out the strands and direct them toward a guide roller 33 mounted rotatabiy on the support 29. The strands engage peripheral grooves 36-36 provided in the roller 38 so as to space the strands 10-10 a distance apart equal to the lateral spacing of the strands on the rollers 17-17 and 13-18. The strands pass around a portion of the roller 38 in a counterclockwise direction (Fig. l) and then around a substantial portion of the capstan 28 in a clockwise direction.

The supply reels 23-23 are held in a stationary position as indicated in Fig. l, and each strand 10 revolves around the upper head of its respective reel as it is withdrawn therefrom. The steel strands 10-10 normally have a tendency to unwind due to their inherent resiliency, and as a result, the outer convolutions on the reel tend to unwind too fast and become entangled and break. To prevent this condition from occurring, each strand engages a guide sheave 40 supported on the end of an arm 41 mounted rotatably on a cap 42 designed to fit neatly over the head of the reel 23 from which the strand is being withdrawn. Suitable friction means, not shown, is provided to retard the rotation of the arm 41 with respect to the cap 42, and thereby prevent the strand from unwinding on the reel.

The strands 10-10 (Figs. 1 and 2) pass from the capstan 28 (Figs. 1 and 2) between the contact rollers of the electroplating apparatus and around a cylindrical capstain 44 mounted on the support 29 at the right hand end of the trough 15. The capstan 44 is driven by an electric motor 46 and has a plurality of peripheral grooves 45-45 which engage the strands and maintain the spacing of the strands provided by the peripheral grooves in the rollers 17-17 and 18-18. The strands pass around a substantial portion of the capstan 44 in a clockwise direction and then engage a roller 47 mounted rotatably on the support 29. The roller 47 is provided with grooves like the grooves in the roller 38, which directs the copperclad strands 13-13 to a bank of sheaves supported rotatably on the support 35 so as to direct their respective strands to sheaves 51-51 which guide their respective strands to distributing heads 52-52 mounted on a shaft 53. The shaft 53 is reciprocated longitudinally (by means not shown), so as to distribute the strands uniformly across the winding surface of take-up reels 55-55 rotatably supported between bearings 56-56 mounted on the support 25. Each take-up reel 55 is driven by a belt 57 which engages a pulley mounted on a line shaft 60, and each of the belts 57-57 is provided with an adjustable idler pulley 58 by means of which the belt can be slackened sufficiently to prevent the line shaft from rotating the reel when it is necessary to remove a full reel from the bearings 56-56 and replace it with an empty reel.

The method of and apparatus for advancing the strands individually from supply reels through an electroplating apparatus at constant linear speed and tension is described and claimed in copending application, Serial Number 238,546, filed July 25, 1951, by V. A. Rayburn for Methods of and Apparatus for Advancing Strands, now Patent 2,717,125 granted February 6, 1955.

The magnetic capstan 28 (Figs. 1 and 3) is designed to hold the steel strands 10-10 magnetically in equally spaced peripheral grooves 62-62 provided therein as the captan is rotated and thereby withdraw the strands from their respective reels 23-23, and deliver them to the capstan 44, positioned at the opposite end of the electroplating apparatus 12 at a constant linear speed. The motor 46 is designed to drive the capstan 44 with a torque which tends to advance the strands 10-10 through the electroplating apparatus at a linear speed greater than that at which they are delivered thereto by the capstan 28. The strands are held magnetically by the capstan 28 with such force that the capstan 44 cannot increase the linear speed of the strands, and consequently, the capstan 44 exerts a predetermined tension on each of the strands as it advances the strands through the electroplating apparatus.

The capstan 28 (Figs. 3 and 4) is a laminated structure in which circular end plates 65 and 66, and circular intermediate plates 67-67, made of a para-magnetic metal, are keyed on a shaft 68 and are spaced apart by annular cores 70-70, also made of a magnetic metal. The plates 67-67 and the cores 70-70 are clamped together between the end plates 65 and 66 by a plurality of tie rods 71-71. Circular bands 72-72, made of a nonmagnetic material such as stainless steel, are fitted into annular shoulders 73-73 formed in the peripheries of the end plates 65 and 66 and the intermediate plates 67-67 so that the bands and the plates form a cylinder having a smooth outer surface. End rings 74-74 and intermediate rings 75-75, made of a magnetic material such as magnetic steel, are positioned over the assembly of the end plates, the intermediate plates and the circular bands, and are spaced apart by thin, annular spacers 76-76, made of a nonmagnetic material such as stainless steel, to magnetically insulate the rings 7474 and 75-75 from each other. End rings 78-78, made of a nonmagnetic material, such as a bronze alloy, are positioned over the end rings 74-74 and intermediate rings 79-79 made of the same nonmagnetic material, are positioned over the steel rings 75-75. The rings 74-74, 75-75, 78-78 and 79-79 are keyed to the end plates 65 and 66, the intermediate plates 67-67 and the annular bands 72-72 by headless set screws 80-80. The outer rings 78-78 and 79-79 preferably are fused to the inner rings 74-74 and 75-75 to provide a tight contact between the rings.

The annular spacers 76-76 (Figs. 3 and 4) have a thickness less than the diameter of the strands 10-10 to be advanced by the capstan 28. The rings 74-74 and 75-75 (Fig. 3) have an external diameter slightly larger than the external diameter of the annular spacers 76-76 positioned between the rings, and the adjacent sides of the rings are beveled to form a plurality of equally spaced, substantially U-shaped grooves between the rings which are designed to receive the strands 10-10 as they pass around the capstan. The outer rings 78-78 and 79-79 also have their adjacent sides beveled so as to form a continuation of the U-shaped grooves formed between the rings 74-74 and 75-75. Thus, the beveled sides of the inner rings 74-74 and 75-75 and the outer rings 78-78 and 79-79 form the peripheral grooves 62-62 which engage the strands 10-10 as they are advanced from their individual supply reels by the capstan 44. The grooves 62-62 extend into the inner rings 74-74 and 75-75 a distance equal to approximately one-half the diameter of the strands 10-10 to be advanced by the capstan 28.

The cores 70-70 have an internal diameter designed to leave an annular clearance 81 (Fig. 3) around the shaft 68, and an external diameter substantially less than the external diameter of the plates 65 and 66 and 67-67. Magnet coils 82-82 are positioned over the steel cores 70-70, as shown in Figs. 3 and 4, and are connected in series with each other. One lead wire 83 of the left hand coil (Fig. 3) and one lead wire 89 (Fig. 4) of the right hand coil are connected to collector rings 84 and 85, respectively, mounted on a plate 86, made of a suitable insulating material, and secured to the shaft 68.

Brushes 87-87 (Fig. 5) are mounted on a brush holder 88 so as to slidably engage the collector ring 84, and brushes 90-90 are mounted on a brush holder 91 so as to slidably engage the collector ring 85 so that the coils 82-82 may be connected to a source of D. C. potential. The shaft 68 is journaled in bearings 93 and 94 and has a sprocket 95 secured on one end thereof which engages an endless chain belt 96 driven by a pulley mounted on the shaft of the motor 30. End plates 100-100, made of a nonmagnetic material, are secured to the end plates 65 and 66 by screws 101-101.

When a suitable D. C. potential is applied across the collector rings 84 and 85, the magnet coils 82-82 generate a magnetic flux which flows through the cores 70-70, the plates 65 and 66 and 67-67, the rings 74-74- and 75-75, and forms an annular magnetic field around the grooves 62-62. In describing the path of the magnetic flux generated by each magnet coil, the respective positions of the magnet coils, the circular plates, the rings and the peripheral grooves with respect to each other shall be identified by counting from left to right, as viewed in Figs. 3 and 4.

The coils 82-82 may be wound around the cores 70-70 in such a direction and connected together and to a source of D. C. potential in such a manner that the first coil 82 generates a magnetic flux which flows through the first core 70 from left to right, and then flows outward radially through the first intermediate plate 67, as indicated by the dotted arrows. Since the bands 72-72 are made of nonmagnetic material, the magnetic flux travels from the first intermediate plate 67 through the second ring 75 from right to left, across the second groove 62 formed between the first and second rings 75-75, through the first ring 75 and across the first groove 62 to the left end ring 74. The flux flows inwardly through the plate 65 and returns to the core 70. Thus, the first magnet coil 82 creates an annular magnetic fieldcompletely around the first and second annular grooves 62-62.

When two of the strands -10 engage the first and second grooves 62-62, the magnetic field generated by the first magnet coil 82 pulls the strands forcibly into the bottoms of these grooves so that the strands bridge the air gaps formed by the grooves and provide a metallic path for flux across the first and second grooves. In this manner the two strands 10- 10 engaging the first and second grooves of the capstan 28 are attracted magnetically to the bottom of the grooves and are held with such force that no slippage occurs between the strands and the capstan 28 due to the pull on the strands by the capstan 44.

The second magnet coil 82 generates a magnetic flux which travels through its core 70 in a direction from right to left, that is, in a direction opposite to the flux generated by the first magnet coil. As a result, the flux generated by the second magnet coil travels through the first intermediate plate 67 outward radially, through the second steel ring 75, across the third groove 62, through the third ring 75 and across the fourth groove 62 into the fourth ring 75. This flux then passes into the second intermediate plate and travels inward radially through the second plate to the second core 70. Thus, the flux generated by the second magnet coil forms an annular mag netic field around the third and fourth grooves 62-62. The two strands 10-10 positioned in the third and fourth grooves 62-62 of the capstan are attracted magnetically into the grooves and complete the metallic path for the flux generated by the second coil, and are prevented from slipping with respect to the capstan as they are advanced through the apparatus 12 by the capstan 44.

The third magnet coil 28 generates a flux which travels through its core in the same direction as the fiuX generated by the first magnet coil travels through its core and creates an annular magnetic field around the fifth and sixth grooves 62-62.

It is believed to be apparent that the odd number coils generate a flux which travels from left to right through their respective cores, that the even number coils generate a flux in their respective cores which travels from right to left, and that the magnetic flux generated by each coil acts on two of the strands engaged by the grooves 62-62 of the capstan. As a result, only one magnet coil is required for each pair of wires to be advanced by the capstan. By virtue of this construction, the capstan 28 may be arranged by selection of the proper number of magnet coils and associated plates and rings to withdraw a substantial number of steel strands 10-10 from their respective supply reels and deliver them to the electroplating apparatus 12 at a constant linear speed.

Operation Let it be assumed that the electroplating apparatus 12 is supplied with the proper cleaning and electroplating solutions, and that all the steel strands 10-10 to be advanced through the electroplating apparatus have been threaded from their respective supply reels around the capstan 28, between the rollers 17-17 and 18-18, and around the capstan 44 to the take-up reels 55-55. Let it also be assumed that the line shaft 60 is rotating at a given speed and that all the idler pulleys 58-58 are adjusted so that the line shaft rotates the take-up reels 55-55. The electric motors 30 and 46 are energized to drive the eapstans 2s and 44, whereupon the capstans withdraw all the strands 10-10 from their individual supply reels and advance them through the electroplating apparatus. The brake arm 41 provided on each cap 42 and the brake sheave 34 hold their respective strands taut between the magnetic capstan 28 and the supply reels from which the strands are being advanced. The magnet coils 82-82 are energized simultaneously with motors 30 and 46, and the limit generated by the coils forms annular magnetic fields around their respective grooves 62-62 which attracts the wires magnetically to the capstan 28 as they advance partially around the periphery of the capstan.

The motor 46 applies a torque to the capstan 44 which tends to advance the strands at a linear speed greater than the speed at which the capstan 28 withdraws the strands from their respective supply reels. The magnet coils of the capstan 28 are designed to generate an annular magnetic field across each of the grooves 62-62 to grip the strands 10-10 magnetically with suflicient force to prevent the strands from slipping in the grooves of the capstan 28 when a predetermined pull is exerted on the strands by the capstan 44. As a result, the capstan 44 advances the strands 10-10 through the electroplating apparatus 12 at a constant linear speed, and maintains a predetermined constant tension on each strand. Thus, the strands 10-10 are advanced individually through the electroplating apparatus 12 at a linear speed and tension which enables the electroplating apparatus 12 to produce copper-clad steel strands 13-13 having a uniform copper coating thereon. The resulting copper-clad strands 13-13 are taken up on the take-up reels 55-55 at substantially uniform tension because the belts 57-57 are designed to slip with respect to their associated reels as the winding diameter of the reels increases from an empty reel to a full reel.

The arrangement of the rings 74-74 and 75-75 and the spacers 76-76 is such that considerable wear may take place in the grooves 62-62 without seriously affecting the ability of the capstan 28 to hold strands against the predetermined pull of the capstan 44. This is due to the fact that as the steel strands cut the grooves 62-62 deeper into the rings 74-74 and 75-75 and the spacers 76-76, the grooves still form an annular air gap in the path of the magnetic flux generated by the coils, and the strands bridge the air gaps as they engage the grooves and provide a metallic path for the magnetic flux across the grooves.

It is to be understood that the coils 82-82 may be wound on their respective cores and connected together in the manner described, but connected to the D. C. potential in a reverse manner. In this case the odd number coils would generate a magnetic flux which travels from right to left through their respective cores, and the even number coils would generate a magnetic flux which would travel from left to right through their respective coils. Such an arrangement would produce an annular magnetic field around each of the grooves 62-62 which would hold the strands 10-10 in the grooves in the manner described. The same result would occur if the coils were wound in an opposite direction to that in which they were wound to produce the flux paths indicated by the arrows on Figs. 3 and 4 of the drawings without changing the polarity of the D. C. potential supplied to the collector rings.

It is to be understood that the term strand as used herein and in the appended claims is intended to include solid wires, stranded wires, tubing, tapes, ribbons and all types of metallic members of relatively small cross section and of indefinite length having a metallic core or covering. Such strands will be made in whole or in substantial part of steel or other suitable para-magnetic material, although for the sake of simplicity such mate- 7 rials are referred to herein and in the annexed claims as magnetic materials.

While the above-described method andapparatus of advancing steel strands is particularly adapted to be used in the manufacture of copper-clad steel strands, it is to be understood that it may be readily modified to advance a plurality of strands individually through various types of apparatus and processes without departing from the spirit and scope of the invention.

What is claimed is:

1. Acapstan for advancing a plurality of filamentary strands made at least in part of a magnetic material, which comprises a rotatable shaft, a plurality of annular coaxial pole pieces made of a magnetic material, said pole pieces being secured fixedly on the shaft and spaced equidistantly apart along the longitudinal axis thereof, a plurality of circular bands made of a nonmagnetic material and positioned between the pole pieces in coaxial relationship therewith, said circular bands bridging the gaps between adjacent pole pieces and cooperating therewith to form a continuous outer cylindrical surface, a series of spaced rings made of a magnetic material and positioned coaxially on and encircling the thus formed cylindrical surface closely, each even ring of said series being positioned wholly on a corresponding nonmagnetic band and each odd ring of said series being positioned partly on a corresponding pole piece and extending laterally over the adjacent nonmagnetic bands at either side of said pole piece, the spacing between adjacent rings being slightly less than the diameters of the filamentary strands to be advanced by the capstan, a plurality of annular spacers made of a nonmagnetic material and so positioned that a spacer is located between each pair of rings, said rings having their adjacent edges beveled and the spacers having external diameters such that peripheral U-shaped grooves for receiving strands are defined between each pair of adjacent rings, means for securing the rings to the periphery of said cylindrical surface for rotation with the shaft, and a plurality of electromagnet coils positioned so that there is one coil located between each two adjacent pole pieces, each of said electromagnet coils being energizable to create a magnetic flux which flows in a magnetic circuit radially through the adjacent pole pieces and transversely through the magnetic rings and across the U-shaped grooves therebetween, adjacent electromagnet coils having opposite polarities whereby said flux is additive within the pole piece positioned therebetween, the magnetic flux across the U-shaped grooves causing the strands positioned in the grooves to be attracted magnetically by coercive forces sufficient to prevent slippage of the strands relative to the rings.

2. A capstan for advancing a plurality of filamentary strands made at least in part of a magnetic material, which comprises a rotatable shaft, a plurality of annular coaxial pole pieces made of a magnetic material, said pole pieces being secured fixedly on the shaft and spaced equidistantly apart along the longitudinal axis thereof, a

. 8 plurality of circular bands made of a nonmagnetic material and positioned between the pole pieces in coaxial relationship therewith, said circular bands bridging the gap between adjacent pole pieces and cooperating therewith to form a continuous outer cylindrical surface, a series of spaced rings made of a magnetic material and positioned coaxially on and encircling the thus formed cylindrical surface closely, each even ring of said series being positioned surrounding wholly on a corresponding nonmagnetic band and each odd ring of said series being positioned partly on a corresponding pole piece and extending laterally over the adjacent nonmagnetic bands at either side of said pole piece, the spacing between adjacent rings being slightly'less than the diameters of the filamentary strands to be advanced by the capstan, a plurality of annular spacers made of a nonmagnetic material and so positioned that a spacer is located between each pair of rings, said rings having their adjacent edges beveled and the spacers having external diameters such that peripheral U- shaped grooves for receiving strands are defined between each pair of adjacent rings, means for detachably securing the rings to the periphery of said cylindrical surface for rotation with the shaft, a plurality of electromagnet coils positioned so that there is one coil located between each two adjacent pole pieces, each of said electromagnet coils being energizable to create a magnetic flux which flows in a magnetic circuit radially through the adjacent pole pieces and transversely through the magnetic rings and across the U-shaped grooves therebetween, adjacent electromagnet coils having opposite polarities whereby said flux is additive within the pole piece positioned therebetween, and a plurality of annular shroud members made of a nonmagnetic material and positioned on and encircling the magnetic rings between the grooves so as to reduce magnetic flux leakage, the magnetic flux across the U-shaped grooves causing the strands positioned in. the grooves to be attracted magnetically by coercive forces sufiicient to prevent slippage of the strands relative to the rings.

References Cited in the file of this patent UNITED STATES PATENTS 1,043,527 Lindquist Nov. 5, 1912 1,230,944 Sundh June 26, 1917 1,263,300 Weston Apr. 16, 1918 1,369,516 Bethke Feb. 22, 1921 1,384,177 Bethke July 12, 1921 1,387,879 Bethke Aug. 16, 1921 1,435,438 Wright NOV. 14, 1922 1,515,719 Bethke et a1. Nov. 18, 1924 1,529,570 Bethke Mar. 10, 1925 1,659,848 Wilson Feb. 21, 1928 1,685,498 McCullough Sept. 25, 1928 1,694,081 Reed Dec. 4, 1928 1,763,092 Clarke June 10, 1930 1,848,856 Wagner et al. Mar. 8, 1932 2,342,850

Perm Feb. 29, 1944 

